It has been proposed to mount air deflectors on the wipers or on the windscreen wiper arms in such a way as to create an aerodynamic effect which acts to apply the wiper against the surface, e.g. glass, to be wiped. Numerous solutions have been proposed with the general aim of creating an over-pressure above the deflector in order to apply the arm and the wiper against the glass surface.
French Patent Application No. 1 173 747 envisages not only causing an over-pressure above the wiper, but also a reduced pressure below the wiper. However, this document does not really relate to a deflector made separately from the wiper and able to be mounted subsequently on the wiper, but rather to a wiper in which the supporting bar or the blade holder has a special profile in order to provide the necessary down-force. This solution cannot be applied to an existing wiper.
A main object of the invention is to provide an inexpensive and simple air deflector which is adapted to be mounted on an existing wiper.